Newark International Airport is located on the boundary between Newark and Elizabeth, New Jersey. The airport is owned by the city of Newark and controlled by the Port Authority of New York and New Jersey. Newark opened on October 1, 1928 as the first major airport in the metropolitan area and rapidly became the world's busiest commercial airport. During World War II the field was taken over for logistics operations by the United State Army. In the 1970 the airport became Newark International Airport. Newark expanded dramatically in the 1980s. In late 1996, the monorail system was designed to connect all three terminals, the overflow parking lots and garages, and the rental car facilities. The extended monorail reached to the new Newark Airport train station on Amtrak's Northeast Corridor line in 2001 and was renamed AirTrain Newark. In 2003, a 325-foot control tower was commissioned, the fourth in the airport's history. In June 2008 the number of flights was restricted to 81 per hour to soothe Newark's congestion. Newark Liberty International Airport has three major terminals: Terminal A, B and C. Terminal A has three concourses A1, A2, and A3 in circular satellite buildings. The main building measures about 800 by 165 feet. A Welcome Center was recently added. Terminal B has extended the level into three levels, presenting new inline baggage screening systems, a passenger screening system, new baggage claim hall, and additional passenger lounges and concessions. Terminal B has 15 international arrivals gates. Terminal C was reconstructed and expanded into doubled the capacity for departures under a $1.2 billion program known as the Continental Airlines Global Gateway Project. Completion of this new design brought the total number of gates to 59 and added another 1,500 passengers-per-hour arrival scale to Newark Liberty. The City of Newark invested more than $8.2 million, the U.S. government spent more than $15.1 million and Port Authority has invested more than $4.3 billion to build and develop the airport. Approximately 20,000 people are employed at Newark Liberty and the airport contributes about $22.9 billion in economic activity to the New York-New Jersey metropolitan region. By extension, the airport leads to about 162,000 jobs and $8.3 billion in annual salaries in the region.